Nasa Goddard Space Flight Centre atmospheric scientist Richard Kleidman spotted a curling plume of smoke above clouds over Canada's Northwest Territories.
He was browsing new imagery captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite.
The smoke was probably from the Alberta fire at Fort McMurray. Other fires in Saskatchewan and Manitoba may have contributed.
Kleidman said: "It is an excellent example of aerosol being transported above clouds-a topic currently of great interest to the aerosol research community."
Aerosols are small airborne particles found in plumes of smoke, air pollution, dust, and volcanic ash.